There has been an interactive communication system using presence technology, generally known as an instant messaging system, for exchanging text or the like with a certain partner. The interactive communication system using presence technology will be described below with reference to FIG. 1.
As shown in FIG. 1, computer terminals 11A, 11B comprise means for sending presence information (hereinafter referred to as presentities 111A, 111B), means for receiving the presence information of the presentities (hereinafter referred to as watchers 112A, 112B), means for transferring the presence information of the presentities to watchers 112A, 112B (hereinafter referred to as presence service 21), means for sending instant messages (hereinafter referred to as senders 113A, 113B), means for receiving instant messages (hereinafter referred to as instant inboxes 114A, 114B), means for transferring an instant message from sender 113A or sender 113B to instant inbox 114A or to instant inbox 114B (hereinafter referred to as instant message service 31), screen output means 115A, 115B for outputting information to screens, and input means 116A, 116B for entering information from users. The present invention referred to above comprises information representative of the states of devices such as computer terminals 11A, 11B, etc. or the states of the users. For example, the present invention comprises information such as “online” or “offline” indicative of whether or not a device is connected to the network, and “available” or “unavailable” indicative of whether or not a user is able to respond immediately.
The interactive communication system using the presence technology, which is constructed above, operates as follows: When user A is desirous of the disclosure of the presence information of user B, watcher 112A which is instructed by user A though input means requests presence service 21 to disclose the presence information of user B. Presence service 21 which has received the request sends an inquiry to presentity 11B of user B or makes a judgement about the request according to a method such as by following a policy stored by present service 21 itself. When the request is permitted by user B, the presence information of user B will subsequently be transferred via presence service 21 to user A.
For sending an instant message from user A to user B, sender 113A which is instructed by user A though input means 116A sends an instant message for user B to instant message service 31. The instant message is then transferred from instant message service 31 to instant inbox 114B of user B.
According to the interactive communication system using the presence technology, it is customary for a user to register a companion user with whom instant messages are to be exchanged in a member list displayed on the screen (hereinafter referred to as a contact list). Based on the contact list, the user can confirm the presence information of the companion user and sends an instant message to the companion user. Generally, when a user is registered in the contact list, the user is notified of the fact that the user has been registered in the contact list by the other user.
Interactive communication systems using the presence technology include an interactive communication system which operates to complete the registration of a companion user in the contact list and confirm the presence information of the companion user after the companion user has given permission about the disclosure of presence information of the companion user, and an interactive communication system which operates to immediately complete the registration of a companion user in the contact list and confirm the presence information of the companion user without the need for permission from the companion user. According to the interactive communication system which completes the registration of a companion user after being permitted by the companion user, it is general practice for the companion user to select “permit” or “refuse” about disclosure of the presence information when the companion user confirms the notification on the screen of the computer terminal.
Another interactive communication system using presence technology allows the companion user to select “permit” or “refuse” as regards the reception of an instant message, in addition to the selection of “permit” or “refuse” as regards the disclosure of the presence information.
According to the interactive communication systems using presence technology, furthermore, when a companion user confirms that a certain user has registered the companion user in the contact list of the user, the companion user can select whether or not to register the user in the contact list of the companion user. Unless the companion user selects “register”, the user is not registered in the contact list of the companion user.
Examples of the interactive communication systems using presence technology are disclosed in JP No. 2005-309500A (pages 3 through 5, FIG. 5) and Document: M. Day et al, “A Model for Presence and Instant Messaging”, RFC2778, February 2000, <http:www.letf org/rfc/rfc2778.txt>.
With the interactive communication systems using presence technology, however, a process of permitting disclosure of the presence information to a companion and a process of registering a companion who has permitted disclosure of the presence information in a contact list are independent of each other, and users do not necessarily mutually permit the disclosure of the presence information and register a companion user in the contact list. For example, user A may register user B in the contact list, whereas user B may not register user A.
As a result, a user who has already been registered in the contact list may refuse the disclosure of the presence information or may refuse the reception of an instant message, and a user who has not been registered in the contact list may permit the disclosure of the presence information or may permit the reception of an instant message.
This is because the registration in the contact list, the permission of the disclosure of the presence information, and the permission of the reception of an instant message are not managed in a set, and all users who have permitted the disclosure of the presence information and all users who have permitted the reception of an instant message cannot be confirmed from only the contact list.
In addition to the above problem in which registration in the contact list, permission of the disclosure of the presence information, and permission of the reception of an instant message are not managed in a set, since users do not necessarily mutually permit the disclosure of the presence information and the reception of an instant message, there is a problem in that all users who have permitted the disclosure of the presence information and all users who have permitted the reception of an instant message cannot be confirmed from only the contact list. As a result, the presence information may be disclosed to a user who has not been registered in the contact list or an instant message may be received from a user who has not been registered in the contact list.